As for the supervision and control system in a power generation plant, the development of devices which are capable of generating executable codes (control program) for the plant controlling from a block diagram, a design document of higher rank, is in progress (for example, refer to Patent Documents 1-5). Here, in the first place, a block diagram is created as a design document of higher rank, using a commercial CAD (Computer Aided Design) tool and others. On the other hand, in order to create a control program from the block diagram, a man interprets at first the block diagrams which are created with the CAD tool. After that, manual efforts will be made to input the logics for control and computing which are designed to operate as intended, using an engineering tool. The engineering tool is connected to input devices, such as a monitor, a keyboard, a mouse, and a touch operation device. In these days, a device which converts from a block diagram that has been created with the CAD tool into the logics for control and computing that can be edited with an engineering tool is also proposed.